Yes as far as I'm aware the SP motors have 0 degrees timing.
If you're looking for a motor on the BRCA legal list then it'll have to be one of the LRP, Nosram or Novak motors. I've not heard of any issues running them on the Speed Passion speedo's. The GT is a great speedo (I've got one as well as a Sphere), I wouldn't bother getting another one just to run a 10.5 with.
I've heard that the Speed Passion and Hacker 10.5 motors are going to go through the homologation process, so they might be approved soon, but as of now they aren't.